200 Yamaha start and run

[Skeeter246]

I’m new to this so my apologies if I ignorantly do something wrong. I’m at my wits end with an ongoing issue and want to see if anyone has some help for me. I have an 03 Yamaha 200 VMAX, I bought a Skeeter ZX200 new in 04, I’ve always ran Ring Free, 99% of the time it’s only had Yamalube in it, up til last year I had ran SeaFoam regularly. Mechanic 2 says that’s a bad idea BTW.??. it’s gave zero trouble and been very well cared for. All I’ve ever done is change plugs yearly (w/NGK) and every year or so a water pump. Around 2016 an issue started, I’ve had it in 2 shops since. Both certified mechanics, not the shade tree variety… although I’m ready to try that if it will help. Off the trailer it starts like new. Every start thereafter it’s hit or miss. Usually I have to have my foot slightly on the hot foot or maybe it will take 6 attempts to start. Then it smokes like a tar kiln and sounds like a 40 YO flooded worn out engine for the first few seconds. The first shop said everything was at factory spec and he took it to the lake and couldn’t duplicate my issue… which I’m highly skeptical of now. The 2nd shop went alway to rebuilding fuel pumps to pull at straws and changed “several filters”. Nothing has changed it. I’m ready to just replace an O2 sensor and see if that will help. Anyone have any suggestions? Sometimes I get 64mph out of it and the next time 56. Smooth as a button running anywhere in the rpm range after the start. Thoroughly confused, yes I am.